Sorry, I didn’t see this earlier. I appreciate the sentiment, but it’s fine—I understand that this can be a very emotional topic if you’re deeply invested in your opinion.
I didn’t posit them, I merely pointed them out; that you continue to ignore them doesn’t mean they’re not there.
That’s an apt notion when we’re talking about conflicting hypotheses, such as whether the Ptolemaic or the Copernican model of the solar system is a better fit; but that’s not what we’re doing here. Rather, we’re looking for reasons—for something that answers a ‘why’ question (which scientific models don’t pretend to do). And as a reason for the movement of cog C, that of cog B simply falls short.
Talking about the movement of cog B does not, in fact, carry any information that isn’t already supplied by the mere fact of the movement of cog C, and thus, in particular, can’t explain the latter—it’s just vacuous in the logical sense. From the fact of the motion of cog C, that of cog B is a given. It tells us nothing new.
Now you might say, but cog C might have moved for a different reason, say, due to a sudden gust of wind or what have you; in that case, pointing to the motion of cog B would eliminate several alternatives, and increase our knowledge of the reason of cog C’s movement, and hence, be explanatorily relevant. But that’s why I said this is a bad analogy: it allows us to posit variability where there is none. Usually, physics is formulated in such a way that the initial data determines all future data, in a deterministic world. But there’s nothing special about the initial data, there. It’s equally as true that the present data determines all data to the future—and to the past. So once you know the conditions at any one given point in time, the conditions at every other point are a simple logical implication of those, and thus, tautological. So, if you know the data at any one point in time, nothing is added by the data at any other point in time.
But then, in particular, if you know the data now, whatever happened one second ago does not add any information—it’s just a restatement of the same information in a different way, a mere tautology. So it can’t be explanatorily relevant to the data now. In fact, if you think it does, consider that you could just as validly point to the data a week from now as explaining what you’re doing right now—so if you were to say, it’s my intention, a second ago, to grab the cup of coffee on my table, that explains my doing so right now, I could equally well say, no, it’s your intention, a week from now, to have a slice of pizza that does so. Both statements are logically equivalent. But then, your intention is wholly inert as an explanation of your actions.
An explanation of cog C’s movement might come from the fact that I rotated cog A, or indeed, I rotated cog C directly, or maybe, I rotated cog D, or even that I rotated all the cogs simultaneously in correct proportion to their gear ratios—but it can’t come from within the chain of implications linking the physical facts at different points in time, because they add nothing. But of course, if you insist on explaining everything in causal terms, that’ll just kick the can further down the road.
I’m not handwaving the problems with free will away—I fully accept them (well, in sensibly stated versions, that is). Again, my agenda isn’t to argue for the reality, or even possibility, of free will. I just point out that the same problems also afflict the notion of causation (and that of chance): in each case, you have to either accept some infinitary notion, or hold that the idea just isn’t sensible. But what you can’t do is to sweep the problem under the rug for one (e.g. causality), while claiming it is terminal for another (free will).
My problem with your line of reasoning isn’t the stance you take that free will is problematic, it’s that you take it to be problematic in a special and absolute sense, and that anybody not following you there is objectively wrong. But really, all you’re doing is expressing a metaphysical preference—which is fine—but presenting it as if it’s an objectively correct choice—which isn’t. It’s all well and good to say that you like red wine better than white, but once you go and then claim that those preferring white wine are objectively wrong, you’ve simply overextended the reach of your position.
That’s not true, of course. We see the state of affairs now; we infer a chain of causality going back billions of years. (It might’ve started just last Thursday…) That’s the same thing as seeing a willed action right now, and inferring the process necessary to bring it about as such. It’s perhaps easier to understand with chance: either you accept that random things happen ‘just so’—thus not appealing to any sort of mechanistic model—or you have to accept some infinitary process bringing it about, if you think a mechanistic explanation is indispensable. Similar with free will: you can either accept that the will determines itself ‘just so’—have it be a causa sui, like initial conditions determining themselves—or you can point to an infinite regression of the will setting itself, if you feel only that sort of thing could be satisfactory.
So, either has the same claim to being ‘the most problem in all of science and philosophy’ (although of course it’s a problem on which science simply has no say)—they’re all the same problem. It’s merely your preference, or perhaps your familiarity with the notion, that makes you look at causality and assume that the problem there isn’t that fundamental, while you take it to be fatal for free will.
Which could just as well be said about causality.